package com.linwen.excise.niuke._40;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

/**
 * @author wlw
 * @date 2023/3/8 10:45 PM
 */
public class _30字符串合并处理 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String a = scanner.nextLine();
        String str = a.replace(" ","");
        List<Character> o1 = new ArrayList<>();
        List<Character> o2 = new ArrayList<>();
        char[] chars = str.toCharArray();
        for (int i = 0; i < str.length(); i++) {
            if(i%2==0){
                o1.add(chars[i]);
            }else{
                o2.add(chars[i]);
            }
        }
        Collections.sort(o1);
        Collections.sort(o2);
        int index = 0;
        StringBuilder sb = new StringBuilder();
        while (index< o2.size()){// o2为奇数，长度肯定大
            if(index==o1.size()){
                sb.append(o2.get(index));
                break;
            }
            sb.append(o1.get(index));
            sb.append(o2.get(index));
            index++;
        }
        System.out.println(sb.toString());

    }
}
